happy-dom/src/canvas/ImageData.ts

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.

import * as PropertySymbol from '../PropertySymbol.js';
import type BrowserWindow from '../window/BrowserWindow.js';
import type ICanvasShape from './ICanvasShape.js';

/**
 * The ImageData interface represents the underlying pixel data of an area of a <canvas> element.
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/API/ImageData
 */
export default class ImageData implements ICanvasShape {
	// Injected by WindowContextClassExtender
	protected declare [PropertySymbol.window]: BrowserWindow;

	public readonly [PropertySymbol.data]: Uint8ClampedArray;
	public readonly [PropertySymbol.width]: number;
	public readonly [PropertySymbol.height]: number;

	/**
	 * Constructor.
	 *
	 * @param dataArray A Uint8ClampedArray containing the underlying pixel representation of the image.
	 * @param width The width of the ImageData, in pixels.
	 * @param height The height of the ImageData, in pixels. If not specified, it is calculated as `dataArray.length / (sw * 4)`.
	 */
	constructor(dataArray: Uint8ClampedArray | number, width: number, height?: number) {
		if (arguments.length < 2) {
			throw new this[PropertySymbol.window].TypeError(
				`Failed to construct 'ImageData': 2 arguments required, but only ${arguments.length} present.`
			);
		}
		if (dataArray instanceof Uint8ClampedArray) {
			if (typeof width !== 'number') {
				throw new this[PropertySymbol.window].TypeError(
					`Failed to construct 'ImageData': The width argument must be a number.`
				);
			}
			if (height !== undefined && typeof height !== 'number') {
				throw new this[PropertySymbol.window].TypeError(
					`Failed to construct 'ImageData': The height argument must be a number.`
				);
			}
			this[PropertySymbol.data] = dataArray;
			this[PropertySymbol.width] = width;
			this[PropertySymbol.height] = height !== undefined ? height : dataArray.length / (width * 4);
		} else {
			if (typeof width !== 'number') {
				throw new this[PropertySymbol.window].TypeError(
					`Failed to construct 'ImageData': The height argument must be a number.`
				);
			}
			this[PropertySymbol.data] = new Uint8ClampedArray(new Array(dataArray * width * 4).fill(0));
			this[PropertySymbol.width] = dataArray;
			this[PropertySymbol.height] = width;
		}
	}

	/**
	 * Returns data.
	 *
	 * @returns Data.
	 */
	public get data(): Uint8ClampedArray {
		return this[PropertySymbol.data];
	}

	/**
	 * Returns width.
	 *
	 * @returns Width.
	 */
	public get width(): number {
		return this[PropertySymbol.width];
	}

	/**
	 * Returns height.
	 *
	 * @returns Height.
	 */
	public get height(): number {
		return this[PropertySymbol.height];
	}
}